The present invention relates to a heat exchanger.
Japanese Patent Application Publication No. 2012-17943 discloses an oil cooler (heat exchanger) arranged to cool an engine oil and so on of a vehicle. In this oil cooler, an offset fin is disposed within a tube through which the oil flows, so as to improve a heat exchanger efficiency.
The offset fin has a corrugated shape which is repeatedly bent at a regular interval. In a planner view, fluid such as the oil can flow in a direction (first direction) along the bending line of the corrugated shape, and in a direction (second direction) perpendicular to the first direction. That is, the offset fin has a shape in which the corrugated shape in the first direction is offset in the second direction at a predetermined interval in the planner view.